Mattress

ABSTRACT

[Problem] The present invention provides the mattress which can fix a plurality of mattresses stably. 
     [Solution] A mattress comprises a first mattress  10 , a second mattress  20  stacked on the first mattress, and a fixing member  30  fixing the first mattress and the second mattress. The fixing member comprising a first belt  31  attached to a side surface of the first mattress, a second belt  33  having a first fixing part and the second fixing part fixed to a lower end part and an upper end part in a side surface of the second mattress, respectively, and a connecting tool  34  passed to the second belt and moving from the upper end part to the lower end part in the side surface of the second mattress. The first mattress and the second mattress are fixed by passing the first belt to the first connecting tool.

TECHNICAL FIELD

The present invention relates to a plurality of mattresses stacked.

BACKGROUND ART

Conventionally, when stacking a plurality of mattresses, the mattressesare merely stacked without fixing mattresses, and are fixed the fourcorners of the mattress by rubber.

PRIOR ART REFERENCE Patent Reference

Patent reference 1: Jpn. Pat. Appln. KOKAI Publication No. 2011-229623Patent reference 2: Jpn. Pat. Appln. KOKAI Publication No. 2002-315651

SUMMARY OF INVENTION Problem to be Solved by Invention

However, gap arises only by stacking a plurality of mattresses. If thefour corners of a mattress are fixed by rubber, feeling of pressure willarise. Thus, it is difficult to fix a plurality of mattresses stably andcomfortably use the mattresses.

Then, the present invention provides the mattress which can fix aplurality of mattresses stably.

Means for Solving Problem

A mattress according to one embodiment of the present inventioncomprising a first mattress, a second mattress stacked on the firstmattress, and a fixing member fixing the first mattress and the secondmattress, the fixing member comprising a first belt attached to a sidesurface of the first mattress, a second belt having a first fixing partand a second fixing part, the first fixing part fixed to a lower endpart in a side surface of the second mattress, and the second fixingpart fixed to an upper end part in the side surface of the secondmattress, and a first connecting tool passed to the second belt andmoving from the upper end part to the lower end part in the side surfaceof the second mattress, the first mattress and the second mattress fixedby passing the first belt to the first connecting tool.

Effect of Invention

The present invention can provide the mattress which can fix a pluralityof mattresses stably.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 The top view shows the mattress stacked in two-stage according toa first embodiment.

FIG. 2 The side view shows the mattress stacked in two-stage accordingto the first embodiment.

FIG. 3 The figure shows the state at the time of separation of themattress stacked in two-stage of FIG. 2.

FIG. 4 The figure shows a state when the mattress stacked in two-stageof FIG. 2 is turned over.

FIG. 5 The front view shows the mattress stacked in two-stage at thetime of fixing according to the first embodiment.

FIG. 6 The side view shows the mattress stacked in two-stage at the timeof fixing according to the first embodiment.

FIG. 7 The enlarged view shows the mattress stacked in two-stage at thetime of separation according to the first embodiment.

FIG. 8 The side view shows the mattress stacked in two-stage at the timeof separation according to the first embodiment.

FIG. 9 The side view shows the mattress stacked in three-stage accordingto a second embodiment.

FIG. 10 The figure shows a state when the mattress stacked inthree-stage of FIG. 9 is separated and it turns over.

FIG. 11 The front view shows the mattress stacked in three-stage at thetime of fixing according to the second embodiment.

FIG. 12 The side view shows the mattress stacked in three-stage at thetime of fixing according to the second embodiment.

FIG. 13 The front view shows the mattress stacked in three-stage at thetime of attachment and detachment according to the second embodiment.

FIG. 14 The side view shows the mattress stacked in three-stage at thetime of attachment and detachment according to the second embodiment.

FIG. 15 The front view shows the mattress stacked in three-stage at thetime of separation according to the second embodiment.

FIG. 16 The side view shows the mattress stacked in three-stage at thetime of separation according to the second embodiment.

FIG. 17 The side view shows the mattress stacked in four or more stageaccording to the second embodiment.

FIG. 18 The side view shows the mattress stacked in four or more stageaccording to the second embodiment.

FIG. 19 The front view shows the mattress stacked in three-stage at thetime of fixing according to a third embodiment.

FIG. 20 The side view shows the mattress stacked in three-stage at thetime of fixing according to the third embodiment.

FIG. 21 The front view shows the mattress stacked in three-stage at thetime of attachment and detachment according to the third embodiment.

FIG. 22 The side view shows the mattress stacked in three-stage at thetime of attachment and detachment according to the third embodiment.

FIG. 23 The front view shows the mattress stacked in three-stage at thetime of separation according to the third embodiment.

FIG. 24 The side view shows the mattress stacked in three-stage at thetime of separation according to the third embodiment.

FIG. 25 The side view shows the mattress stacked in four or more stageaccording to the third embodiment.

FIG. 26 The side view shows the mattress stacked in four or more stageaccording to the third embodiment.

MODES FOR CARRYING OUT INVENTION

Hereinafter, referring to an attached drawing, it describes about anembodiment. In the following descriptions, a common reference mark isattached about the element which has the same function and composition.

[1] First Embodiment

The first embodiment is an example at the time of making a mattress intoa stacked two-stage.

[1-1] Entire Structure

FIG. 1 and FIG. 2 show the top view and the side view of the mattressstacked in two-stage according to a first embodiment. Hereinafter, itdescribes about the entire structure of the mattress stacked intwo-stage according to a first embodiment.

As shown in FIG. 1 and FIG. 2, in the first embodiment, the twomattresses 10 and 20 are stacked, and the mattresses 10 and 20 are fixedwith the fixing member 30.

The mattress 10 comprises the spring part 10 a which has a plurality ofsprings and the cushion part 10 b. The spring part 10 a and the cushionpart 10 b have the structure of a common mattress.

The mattress 20 comprises a cushion part and has thickness of about thesame as the cushion part 10 a of the mattress 10.

Every two fixing members 30 are provided by the both side surfaces inthe longitudinal direction of the mattresses 10 and 20, respectively,and are fixing the mattresses 10 and 20 at four places, for example.However, a fixed place is not limited to the position or number toillustrate, but can be changed variously. It is desirable that thedistance D from the end of the side surface of the mattresses 10 and 20to the fixing member 30 is equal to each other.

[1-2] Reversible Function

FIG. 3 shows the state at the time of separation of the mattress stackedin two-stage of FIG. 2, and FIG. 4 shows a state when an upper mattress(topper is called hereafter) is over turned among the mattresses stackedin two-stage of FIG. 2. Hereinafter, it describes about the reversiblefunction of the mattress stacked in two-stage according to the firstembodiment.

As shown in FIG. 3 and FIG. 4, the topper 20 can be turned over andused. That is, the topper 20 can also use the A surface as the frontsurface, and the B surface as the front surface.

The front surface and the back surface (the A surface and the B surface)have a different material of resilience, breathability, and moistureretention, for example. The topper 20 has low rebounding, highrebounding, an object for summer, an object for winter, etc. Thereby,the topper 20 is usable in reversible according to liking of a seasonand a user.

[1-3] Fixing and Separation Method

FIG. 5 and FIG. 6 show the enlarged view of the mattress stacked intwo-stage at the time of fixing according to the first embodiment. FIG.7 and FIG. 8 show the enlarged view of the mattress stacked in two-stageat the time of separation according to the first embodiment.Hereinafter, it describes about the fixing and the separation method ofthe mattress stacked in two-stage according to the first embodiment.

As shown in FIG. 5 and FIG. 6, the fixing member 30 for fixing when themattress 10 and the topper 20 are stacked, is provided. The fixingmember 30 has the belts 31 and 33 and the ring (connecting tool) 34.

The belt 31 is attached to the side surface of the mattress 10. The oneend of the belt 31 is fixed to the lower end part (fixing part 11) inthe side surface of the cushion part 10 b of the mattress 10. The lengthof the belt 31 has a desirable degree (for example, about 2 times of thethickness of the cushion part 10 b of the mattress 10) which can befolded back through the ring 34.

Velcro 32 a and 32 b is provided by the surface of the both ends of thebelt 31, respectively. As for Velcro 32 a provided near the fixing part11 of the belt 31, it is desirable for area to be wider than Velcro 32 bprovided near the end of the belt 31. Instead of Velcro 32 a and 32 b,it may be any fixable member, such as a snap button.

The belt 33 is attached to the side surface of the topper 20. One end ofthe belt 33 is fixed to the lower end part (fixing part 21) in the sidesurface of the topper 20, and the other end of the belt 33 is fixed tothe upper end part (fixing part 22) in the side surface of the topper20.

The fixing method of the belts 31 and 33 may be sewn in to the tape edgeof the mattress 10 and the topper 20, and may be fixed with a tag pinetc., for example. As the belts 31 and 33, cloth, vinyl, leather, etc.are used, for example.

The ring 34 is passed through the belt 33 of the topper 20. The ring 34is movable and it can move it freely from the upper end part (fixingpart 22) to a lower end part (fixing part 21) in the side surface of thetopper 20. The ring 34 consists of a buckle material (for example, ironand a nickel plate), a plastic, a synthetic resin, etc., for example.The ring 34 may be in any shape, such as a square, a rectangle, ahexagon, a circle, and an ellipse, for example. Although one ring 34 isprovided to the one belt 33, the ring 34 may be provided two or more tostrengthen more.

As shown in FIG. 7 and FIG. 8, Velcro 32 a and 32 b of the belt 31 ofthe mattress 10 are peeled and the belt 31 is removed from the ring 34at the time of separation of the mattress 10 and the topper 20. Whenusing the B surface of the topper 20 as the front surface, the topper 20is turned over, the belt 31 is passed through the ring 34 and is fixedby Velcro 32 a and 32 b. At this time, because the ring 34 of the fixingmember 30 can move the belt 33 freely up and down, even if turn over thetopper 20, the position which fixes the mattress 10 and the topper 20does not change.

[1-4] Effect

According to the first embodiment, when the mattress 10 and topper 20are stacked into two-stage, by fixing the mattress 10 and the topper 20with the fixing member 30, generating of gap is inhibited and morestable use is enabled.

Even if the topper 20 is turned over, the ring 34 passed to the belt 33can move to go up and down freely, and the mattress 10 and the topper 20can be fixed. Thus, also when the topper 20 is usable in reversible, themattress 10 and the topper 20 can be stably fixed by using the ring 34of working.

The topper 20 can be used reversibly in the front surface and the backsurface. That is, it can turn over by removing the fixing member 30, andcan use it stably. For this reason, the adjustment according to hardnessand a season can be used by using the cushion with which hardness andbreathability etc. are different in the front surface and the backsurface of the topper 20.

In the first embodiment, the state (the state of using the A surface,and the state of using the B surface) which attached the topper 20, andthe state which the topper 20 is removed, three kinds of feeling in bedcan be changed freely.

The mattress 10 and the topper 20 are fixed with the fixing member 30 atfour places. By this, unlike the case of using the fastener and sewingof the whole circumference, it can reduce the feeling of pressure whensleeping and be used comfortably.

The topper 20 can be removed from the mattress 10. For this reason,another person is used as a mattress the removed topper 20 in differentplaces. The removed topper 20 can be used separately to the mattress 10of the body.

Since the conventional mattress is heavy, it is difficult to shade-dry.On the other hand, in the first embodiment, since the topper 20 isseparable, it becomes easy to dry the topper 20.

When the topper 20 is exhausted, it can be used for a long time themattress 10 itself by exchanging only the topper 20.

[2] Second Embodiment

The second embodiment is an example at the time of making a mattressinto a stacked three-step. In the second embodiment, it mainly describesabout a different point from the first embodiment.

[2-1] Entire Structure

FIG. 9 shows the side view of the mattress stacked in three-stageaccording to the second embodiment. FIG. 10 shows separation of themattress stacked in three-stage of FIG. 9, and a state when it turnsover. Hereinafter, it describes about the entire structure of themattress stacked in three-stage according to the second embodiment.

As shown in FIG. 9 and FIG. 10, in the second embodiment, the threemattresses 10, 20, and 40 are stacked, and the mattresses 10, 20, and 40are fixed with the fixing member 30.

Among the mattresses 10, 20, and 40, the two upper mattresses 20 and 40(topper is called hereafter) can separate from the mattress 10, and canuse by turning over. The topper 40 has structure which is different withthe front surface and the back surface (A surface and B surface) likethe topper 20 of the first embodiment. It is also possible to place thetopper 40 directly on the mattress 10 by replacing the topper 20 and thetopper 40.

Every two fixing members 30 are provided by the both side surfaces inthe longitudinal direction of the mattress 10 and the topper 20 and 40,respectively, and are fixing the mattress 10 and the topper 20 and 40 atfour places, for example. However, a fixed place is not limited to theposition or number to illustrate, but can be changed variously. It isdesirable that the distance D from the end of the side surface of themattresses 10 and the topper 20 and 40 to the fixing member 30 is equalto each other.

[2-2] Fixing, Attachment and Detachment, and Separation Method

FIG. 11 and FIG. 12 show the enlarged view of the mattress stacked inthree-stage at the time of fixing according to the second embodiment.FIG. 13 and FIG. 14 show the enlarged view of the mattress stacked inthree-stage at the time of attachment and detachment according to thesecond embodiment. FIG. 15 and FIG. 16 show the enlarged view of themattress stacked in three-stage at the time of separation according tothe second embodiment. Hereinafter, it describes about fixing of themattress stacked in three-stage, attachment and detachment, andseparation method according to the second embodiment.

As shown in FIG. 11 and FIG. 12, The fixing member 30 for fixing whenthe mattress 10 and the topper 20 and 40 are stacked, is provided. Thefixing member 30 has the belts 31, 33, and 36 and the rings (connectingtool) 34 and 37.

The belt 31 is the same structure as the first embodiment. That is, oneend of the belt 31 is fixed to the lower end part (fixing part 11) inthe side surface of the cushion part 10 b of the mattress 10, and Velcro32 a and 32 b is provided by the surface of the both ends of the belt31, respectively.

The belt 33 is attached to the side surface of the topper 20. The belt33 has the first portion 33 a, the second portion 33 b, and the centerportion 33 c. The boundary part of the first portion 33 a and the centerportion 33 c of the belt 33 is fixed to the lower end part (fixing part21) in the side surface of the topper 20, and the boundary part of thesecond portion 33 b and the center portion 33 c of the belt 33 is fixedto the upper end part (fixing part 22) in the side surface of the topper20. The length of the belt 33 has a desirable degree (for example, about3 times of the thickness of the topper 20) which can be folded backthrough the rings 34 and 37.

Velcro 35 a and 35 c is provided to both sides of the first portion 33 aon the belt 33, respectively, Velcro 35 b is provided on the secondportion 33 b, and Velcro 35 d is provided on the center portion 33 c. Atthe time of fixing, Velcro 35 a and 35 b is fixed, and Velcro 35 c and35 d is fixed.

At the time of fixing, the end of the first portion 33 a of the belt 33is fixed to near the fixing part 22 by Velcro 35 c and 35 d, and the endof the second portion 33 b of the belt 33 is fixed to near the fixingpart 21 by Velcro 35 a and 35 b. That is, the belt 33 at the time offixing has a three-layer structure which the center portion 33 c, thefirst portion 33 a, and the second portion 33 b stacked in order.

The belt 36 is attached to the side surface of the topper 40, and hasthe same structure as the belt 33. That is, the belt 36 has the firstportion 36 a, the second portion 36 b, and the center portion 36 c. Theboundary part of the first portion 36 a and the center portion 36 c ofthe belt 36 is fixed to the lower end part (fixing part 41) in the sidesurface of the topper 40, and the boundary part of the second portion 36b and the center portion 36 c of the belt 36 is fixed to the upper endpart (fixing part 42) in the side surface of the topper 40. The lengthof the belt 36 has a desirable degree (for example, about 3 times of thethickness of the topper 40) which can be folded back through the ring37.

Velcro 38 a and 38 c is provided to both sides of the first portion 36 aon the belt 36, respectively, Velcro 38 b is provided on the secondportion 36 b, and Velcro 38 d is provided on the center portion 36 c. Atthe time of fixing, Velcro 38 a and 38 b is fixed, and Velcro 38 c and38 d is fixed.

At the time of fixing, the end of the first portion 36 a of the belt 36is fixed to near the fixing part 42 by Velcro 38 c and 38 d, and the endof the second portion 36 b of the belt 36 is fixed to near the fixingpart 41 by Velcro 38 a and 38 b. That is, the belt 36 at the time offixing has a three-layer structure which the center portion 36 c, thefirst portion 36 a, and the second portion 36 b stacked in order.

The fixing method of the belts 31, 33, and 36 may be sewn in to the tapeedge of the mattress 10 and the topper 20 and 40, and may be fixed witha tag pin etc., for example. As the belts 31, 33, and 36, cloth, vinyl,leather, etc. are used, for example.

The ring 37 is passed through the belt 36 of the topper 40. The ring 37is movable and it can move it freely from the upper end part (fixingpart 42) to a lower end part (fixing part 41) in the side surface of thetopper 40.

As shown in FIG. 13 to FIG. 16, Velcro 32 a and 32 b of the belt 31 ofthe mattress 10 are peeled and the belt 31 is removed from the ring 34at the time of separation of the mattress 10 and the topper 20 and 40.Velcro 35 a, 35 b, 35 c, and 35 d of the belt 33 of the mattress 20 arepeeled and the belt 33 is removed from the ring 37. For example, whenusing the B surface of the topper 40 as the front surface, the topper 40is turned over, the belt 33 is passed through the ring 37, and is fixedby Velcro 35 a, 35 b, 35 c, and 35 d. At this time, because the ring 37of the fixing member 30 can move the belt 36 freely up and down, even ifturn over the topper 40, the position which fixes the topper 20 and 40does not change.

[2-3] Effect

It not only can obtain the same effect as the first embodiment of theabove, but according to the second embodiment, it can obtain the stillmore nearly following effects.

According to the second embodiment, the mattresses 10, 20, and 40 arestacked three steps. For this reason, the two topper 20 and 40 can beused removing it, and this two topper 20 and 40 can be arrangedhorizontally, and it can be used as a mattress of double size.

The belts 33 and 36 of the topper 20 and 40 are the same structures. Bythis, the state which attached the topper 20 on the mattress 10 (thestate of using the A surface and the state of using the B surface of thetopper 20), the state (the state of using the A surface and the state ofusing the B surface of the topper 40) which attached the topper 20 and40 on the mattress 10, and the state where the topper 20 and 40 isremoved, five kinds of feeling in bed can be changed freely. In thesecond embodiment, as shown in FIG. 17 and FIG. 18, it is also possibleto stack a mattress on four or more steps.

[3] Third Embodiment

The third embodiment is a modification of the second embodiment and howto fix the belts 33 and 36 of the fixing member 30 differs. In the thirdembodiment, it mainly describes about a different point from the firstand the second embodiments.

[3-1] Fixing, Attachment and Detachment, and Separation Method

FIG. 19 and FIG. 20 show the enlarged view of the mattress stacked inthree-stage at the time of fixing according to the third embodiment.FIG. 21 and FIG. 22 show the enlarged view of the mattress stacked inthree-stage at the time of attachment and detachment according to thethird embodiment. FIG. 23 and FIG. 24 show the enlarged view of themattress stacked in three-stage at the time of separation according tothe third embodiment. Hereinafter, it describes about fixing of themattress stacked in three-stage according to the third embodiment,attachment and detachment, and separation method.

As shown in FIG. 19 to FIG. 24, in the third embodiment, a differentpoint from the second embodiment is a fixing method of the belts 33 and36. At the third embodiment, the end of the first portion 33 a and theend of the second portion 33 b of the belt 33 are fixed to the center ofthe center portion 33 c by Velcro 35 a, 35 b, 35 c, and 35 d and the endof the first portion 36 a and the end of the second portion 36 b of thebelt 36 are fixed to the center of the center portion 36 c by Velcro 38a, 38 b, 38 c, and 38 d at the time of fixing of a mattress. The belts33 and 36 are stacked in two-layer at the time of fixing of the mattress10 and the topper 20 and 40. The length of the belts 33 and 36 has adesirable degree (for example, about 2 times of the thickness of thetopper 20 and 40) which can be folded back through the rings 34 and 37.

Velcro 32 a and 32 b of the belt 31 of the mattress 10 are peeled andthe belt 31 is removed from the ring 34 at the time of separation of themattress 10 and the topper 20 and 40. Velcro 35 a, 35 b, 35 c, and 35 dof the belt 33 of the mattress 20 are peeled and the belt 33 is removedfrom the ring 37. For example, when using the B surface of the topper 40as the front surface, the topper 40 is turned over, the belt 33 ispassed through the ring 37, and is fixed by Velcro 35 a, 35 b, 35 c, and35 d. At this time, because the ring 37 of the fixing member 30 can movethe belt 36 freely up and down, even if turn over the topper 40, theposition which fixes the topper 20 and 40 does not change.

[3-2] Effect

It not only can obtain the same effect as the above the first and thesecond embodiments, but according to the third embodiment, it can obtainthe still more nearly following effects.

According to the third embodiment, the belts 33 and 36 have stacked intwo-layer at the time of fixing of the mattress 10 and the topper 20 and40. For this reason, rather than the second embodiment stacked inthree-layer, the fixing member 30 can be downsized and fine sight naturecan also improve.

In the third embodiment, as shown in FIG. 25 and FIG. 26, it is alsopossible to stack a mattress on four or more steps.

Although the embodiments of the present invention are described, theseembodiments are shown as an example and limiting the scope of inventiondoes not have intention of them. These new embodiments can be carriedout with other various forms, are the ranges which do not deviate fromthe summary of invention, and versatility can omit and replace them andthey can be changed.

DESCRIPTION OF REFERENCE NUMERALS

-   10 Mattress-   11, 21, 22, 41, and 42 Fixing part-   20 and 40 Topper (mattress)-   30 Fixing member-   31, 33, and 36 Belt-   32 a, 32 b, 35 a, 35 b, 35 c, 35 d, 38 a, 38 b, 38 c, and 38 d    Velcro-   34 and 37 Ring.

1: A mattress comprising a first mattress, a second mattress stacked onthe first mattress and being usable in reversible, and a fixing memberfixing the first mattress and the second mattress, the fixing membercomprising a first belt having one end fixed to a lower end part of aside surface of the first mattress, a second belt having a first fixingpart and a second fixing part, the first fixing part fixed to a lowerend part in a side surface of the second mattress, and the second fixingpart fixed to an upper end part in the side surface of the secondmattress, a first connecting tool passed to the second belt and movingfrom the upper end part to the lower end part in the side surface of thesecond mattress, the first mattress and the second mattress fixed bypassing the first belt to the first connecting tool, and a first memberattached to the first belt, the first belt folded back on the outsidethrough the first connecting tool near the first fixing part or thesecond fixing part of the second belt, and the first member for fixingin overlapping the folded first belt on the side surface of the firstmattress, and wherein the one end and the other end of the first beltare fixed on the lower end parts of the side surface of the firstmattress by the first member when fixing the first mattress and thesecond mattress. 2: The mattress according to claim 1, furthercomprising a third mattress stacked on the second mattress and beingusable in reversible, and wherein the fixing member fixes the firstmattress, the second mattress, and the third mattress, the second belthas a first portion, a second portion, and a first center portion placedbetween the first portion and the second portion, the first fixing partis placed at a boundary of the first portion and the first centerportion, the second fixing part is placed at a boundary of the secondportion and the first center portion, at the time of fixing of the firstto third mattresses, the second belt has a three-layer structure whichthe first portion and the second portion piled up on the first centerportion, and the fixing member further comprises a second memberattached to the second belt and for fixing in overlapping the firstportion and the second portion on the first center portion, a third belthaving a third fixing part and a fourth fixing part, the third fixingpart fixed to a lower end part in a side surface of the third mattress,and the fourth fixing part fixed to an upper end part in the sidesurface of the third mattress, and a second connecting tool passed tothe third belt and moving from the upper end part to the lower end partin the side surface of the third mattress, the second mattress and thethird mattress fixed by passing the second belt to the second connectingtool. 3: The mattress according to claim 2, wherein the third belt has athird portion, a fourth portion, and a second center portion placedbetween the third portion and the fourth portion, the third fixing partis placed at a boundary of the third portion and the second centerportion, the fourth fixing part is placed at a boundary of the fourthportion and the second center portion, at the time of fixing of thefirst to third mattresses, the third belt has a three-layer structurewhich the third portion and the fourth portion piled up on the secondcenter portion, and the fixing member further comprises a third memberattached to the third belt and for fixing in overlapping the thirdportion and the fourth portion on the second center portion. 4: Themattress according to claim 1, further comprising a third mattressstacked on the second mattress and being usable in reversible, andwherein the fixing member fixes the first mattress, the second mattress,and the third mattress, the second belt has a first portion, a secondportion, and a first center portion placed between the first portion andthe second portion, the first fixing part is placed at a boundary of thefirst portion and the first center portion, the second fixing part isplaced at a boundary of the second portion and the first center portion,at the time of fixing of the first to third mattresses, an end of thefirst portion and an end of the second portion are fixed to a center ofthe first center portion, and the fixing member further comprises asecond member attached to the second belt and for fixing the end of thefirst portion and the end of the second portion on the center of thefirst center portion, a third belt having a third fixing part and afourth fixing part, the third fixing part fixed to a lower end part in aside surface of the third mattress, and the fourth fixing part fixed toan upper end part in the side surface of the third mattress, and asecond connecting tool passed to the third belt and moving from theupper end part to the lower end part in the side surface of the thirdmattress, the second mattress and the third mattress fixed by passingthe second belt to the second connecting tool. 5: The mattress accordingto claim 4, wherein the third belt has a third portion, a fourthportion, and a second center portion placed between the third portionand the fourth portion, the third fixing part is placed at a boundary ofthe third portion and the second center portion, the fourth fixing partis placed at a boundary of the fourth portion and the second centerportion, at the time of fixing of the first to third mattresses, an endof the third portion and an end of the fourth portion are fixed to acenter of the second center portion, and the fixing member furthercomprises a third member attached to the third belt and for fixing theend of the third portion and the end of the fourth portion on the centerof the second center portion. 6: The mattress according to claim 1,wherein the second mattress has a front surface and a back surface madeof different materials. 7: The mattress according to claim 2, whereinthe third mattress has a front surface and a back surface made ofdifferent materials. 8: The mattress according to claim 1, wherein alength of the first belt is twice a thickness of the first mattress.